Effects of oral administration of trimebutine on colonic propulsion in conscious mice were studied by measuring the time required to evacuate a bead which had been inserted into the colon, and compared with those of metoclopramide and domperidone. In normal animals, trimebutine (10 and 50 mg/kg), metoclopramide (50 mg/kg) and domperidone (50 mg/kg) had no effect on the bead evacuation. Metoclopramide and domperidone at 30 mg/kg showed no effect on the delay of colonic propulsion induced by clonidine, while trimebutine (10 and 30 mg/kg) restored the delay significantly. Trimebutine also showed restoration of the delay induced by loperamide. On the acceleration of the propulsion induced by neostigmine, trimebutine (10 and 30 mg/kg) showed an inhibition. In addition, trimebutine (3-30 mg/kg) dose-dependently suppressed the development of soft feces and/or diarrhea induced by neostigmine. According to the results, it is concluded that trimebutine produces both acceleration and inhibition on the colonic propulsion in mice.